Speed-change gearing.



PATENTED MAY 5, 1908.

E. J. MOGLELLAN. SPEED CHANGE GEARING.

APPLICATION FILED SEPT. 7. 1907.

'3 SHEETS-SHEET 1.

No. 887,010. PATENTED MAY 5 1908. E. J. MQOLELLAN.

SPEED CHANGE GEARING.

APPLIOATION VPILED SEPT. 'i, 1907.

3 SHEETS-SHEET 2.

PATENTED MAY 5, 1908.

E. J. MOCLELLAN.

SPEED GHANGE GEARING.

APPLICATION FILED SEPT. 7, 1907.

3 SHEETS-SHEET 3.

rmrrnn s ra r nts rarmsir orrron.

EDWARD J. MCOLELLAN, OF NEW YORK, N. Y., ASSIGNOR TO THE GARVIN MACHINE COMPANY,

' A CORPORATION OF NEW YORK.

SPEED-CHANGE GEARING.

Applicationfiled September 7, 1907. Serial No. 391,765.

To all whom it may concern:

Be it known that I, EDWARD J. MoCLELLAN, a citizen of the United States, residing at the city of New York, in thecounty of New York and State of New York, have invented certain new and useful Improvements in Speed- Ohange Gearings, of which the following is a full, clear, and exact description.

My invention relates to a change speed transmission system particularly for use in machine tools and analogous uses where it is desired to have a wide range of speeds for the cutting tool or the work feed, or both.

An important need for mechanism of this sort occurs in milling machines where the work is fed against a continuously rotating cutter. Milling machines are now used for almost every kind of machine work and with all ordinary materials, but in order to obtain good results the speed of the cutter and the speed of the work shQuld be widely varied for different materials and different kinds or stages of work. But although such a wide adjustment in the matter of cutter speed and work feed is necessary or desirable, the mechanism should nevertheless be extremely positive under all circumstances. There should be no reliance put on friction drives or other factors of uncertain value.

In carrying out the present invention I have aimed to provide a mechanism for driving the cutter and feeding the work table with great strength and .positiveness, but which is adjustable to a very wide range and number of speeds.

The essential characteristic of the present invention by which these results are secured is the provision of a differential gear motion,

the multiplying or reducing value of which is determined by two separate :adjustments both of which may be independently varied. As will later appear, it is possible to obtain an extremely large number of speed change ratios in this'way.

In the drawings: Figure 1 is a generally sectional view of a speed change transmission system embodying the principles of my invention; in this view the greater part of the casing is removed';-the section is taken on the line II of Fig. 2, looking in the direction of the arrows; Fig. 2 is a vertical sectional view of the same; Fig. 3 is a view similar to Fig. 1 from the opposite side of the machine, being taken on the line IIIIII of Fig. 2, looking in the direction of the arrows.

Specification of Letters Patent.

Patented May 5, 1908.

Referring to the drawings in which like parts are'designated by the same reference sign, 1 indicates a driving shaft, having a pulley, 2, which may be belted or connected to any suitable power source.

3 denotes a driven shaft, upon the end of which may be directly mounted a milling cutter.

4 indicates an additional driven shaft which is in a position to operate the work table feed in any ordinary milling machine as usually constructed. Each of the shafts 3 and 4 is driven from the sh aft 1 through a differential gear train, the increasing or reducmg value of WlllCh may be varied. For this .purpose I have illustrated a preferred construction in which each of the shafts 3 and 4 has permanently keyed or fixed thereto a block or disk 5, which carries bevel gears 6.

Each bevel gear 6 is freely revoluble on its supporting block 5 on an axis radial to the supporting shaft.

-7- and 8 designate bevel gears. sleeved loosely on the shafts 3 and 4 and meshing with the bevel gears 6. The supporting sleeves forthese bevel gears 7 and 8 are indicated at 9 and 9, and they are all'longitudinally s plined, slotted. or formed to slidably receive spur gears 10 and 11 thereon. These spur gears are therefore constrained to rotate with their connected bevel gear, but may be longitudinally positioned wherever desired.

The means for longitudinally positioning these spur gears-10 and 11 include angularly and laterally movable frames 12 and 13,

which are formed to loosely surroundsaid spur gears, and are loosely guided on the sleeves 9, 9'. handles projecting therefrom by which they are moved both angularly and longitudinally on their supporting sleeves. These handles are designated 14 and 15, and are bent in any suitable way to pass through holes or openings in the casing of the machine.

Each handle has a ortion 16, directly overlying a plate 17 of t 1e casing of the machine. Each such handle portion 16 has a bolt 18,

movable therein and cooperating with holes All of these frames have Each of the frames 12 and 13 carries a plurality of gears all permanently in driving noted that the driving shaft 1 has a plurality of gears 29', 29 29 and 29 and also -31,

31 31 31". These gears are permanently fixed to their su porting shaft, and are pref erably all of di erent sizes and disposed in cones, as shown. The pitch of all the spur gears of the mechanism is made the same so it is evident that an intermeshing engagement may be made between idlers 24, 25 and 26, and any selected gears 29, 29 etc., 31 31 etc., as desired, by moving the frames 12 and 13 through their respective handles 16. The frames 12 are capable of making onlyone such meshing engagement when in any particular plane, but the frames 13 are capa 1e of making two intermeshing engagements for each plane of their disposition, respectively through the idlers 25 and 26, such respective engagements pr6- ducing rotation of gears 11 in op osite directions. The disposition of the ho cs 19 is such that the various frames are locked when in their proper meshin engagements, and it will be observed that there are double series of holes for the frames 13, while only a single series is provided for the frames 12, as required. The frames 12 have, however, one single additional hole 32, with which bolts, 18 may cooperate, and when locked in the position of this hole, idlers 24 engage short rack sections 33, which preclude gears 10 from any movement. The idlers 24 are of course-in planes out of mesh with the 'vari-' ous cone gears at this time.

The operation is as follows: Power being applied to the driving pulley 2, the shaft 1 is rotated with its various gears 29', 29 etc.,31,31 etc. -.Theva'riousf rames 12 and 13 being locked in any position, it

I is evident that gear transmission trains are established which rotate the bevel gears 7 and 8 at certain definite speeds. For each change of position of a frame 12 or 13, the correspondlng bevel gear is rotated at a different speed. From the bevel gears 7 and 8 the shafts 3 and 4 are driven through the disks or blocks 5, carrying the idle bevel gears 6, which act as an ordinary difierential train or mechanism. The speed of driven shafts 3 and 4 will be equal to one-half the sum of the s eeds of their corresponding bevel gears 7 an 8, whatever values these may be, either positive or negative;

In a milling machine it may be necessary to drive the cutter only a few revolutions a minute at one time, while at another time it ma be called u on to have a speed of severa hundredR. .M' Such changes amounting .to several hundred fold are practically impossible with anysimple cone gear drive, but they may be freely obtained by my differ ential mechanism. For exam le, sup osing the bevel gear 7 had a speed 0 500 R l M in one direction while bevel gear 8 had a speed of 480 R P M fin the other direction, it is evident that the driven shaft 3 would have a resultant speedof only 1.0 R P M. If, however,

bevel gears 7 and 8 rotated at the speeds noted in the same direction, the driven shaft 3 would have a resultant velocity of 490R P M. It is clear that this change amounts to nearly fifty fold, but'it is accomplished by only-very slight differences in the pitch d1 ameter of-thegears 29, 29 etc., 31, 31 etc., altogether withinthe limits of practical construction. A very' great range of possible s eed adjustments is thus obtainable and at t e same time a large number of ratio values Withthe construction. shown, it is obviously possible to have thirtysix different (gear combinations for driving the cutter an the work table, and as each of these is abso lutely inde endent of the other,'one thousand two undred and ninety-six difierent speed ratios are obtained between the cutter and the work (providing none of the separate the same number for driving gear trains give identical results). The .100

present mechanism therefore provides for a wide range and a large number of speed .ratics in a milling machine.

' What I claim, is

1. In a change speed mechanism, a differ-. ential gear train having a driven member and two rotating devices individually and independently communicating motion thereto, and two separate independent means each including cone gears and a pinion longitudinally movable with respect thereto to selectively mesh therewith, said means acting on said respective devices, for changing the speed of either independentl of the other.

2. In a change speed mec anism, a differential gear train having a driven member and two rotating devices lndividually and independent-1y communicatmg motion thereto,

and two separate independent means each including cone gears and a mion longitudinally movable with respect t ereto to selectively mesh therewith, said means acting on said respective devices for changing the speed and direction of rotation of one independently of the other.

3. In a change speed mechanism, a difierential gear train having a driven member and two rotating devices individually and independently communicating motion thereto,

and two separate independent means each and adapted to independent including cone gears and a pinion longitudinally movable with respect thereto to selectively mesh therewith, said means acting on said respective devices, for locking one against movement and changing the speed of the other. I

4. In a change speed mechanism, a differential gear train having a driven member and two rotating devices individually and independently -communicating motion thereto and two separate independent means each including cone gears and a pinion longitudinally movable with respect thereto to selectively mesh therewith, said means acting on said respective devices for locking one against movement and changing the speed and direction of rotation of the other.

5. In a change speed mechanism, a driven member, a gear carried thereby and two de- I vices including gears meshing with said gear y communicate motion thereto, and means each including cone gears and a pinion longitudinally movable with respect thereto to selectively mesh therewith, said means for varying the relative speeds and direction of'rotation of said devices.

6. In a machine tool, driven shafts for the cutter and for the work feed, a driving shaft, two sets of cone gears thereon, a differential train of gears driven by any one gear of each of the two sets of cone gears, for driving the cutter shaft, and another differential gear train meshing with any one gear of each of the same two sets of cone gears, for operating the work feed.

In witness whereof, I subscribe my signature, in the presence of two witnesses.

EDWARD J. McCLELLAN. Witnesses:

Urns. T. LUTHER, J. T. WILLIAMS. 

